Comparative analysis of new plastid markers for Cryptophytes diversity

Abstract

Cryptophytes are a group of unique eukaryotic algae with the nucleomorph originated from red algae, which provides evidence of the secondary endosymbiosis. Cryptophytes are one of important components of the coastal ecosystem and some lineages contribute to significant algal blooms from winter to spring at the southwestern region of the South Sea and near Jejudo. Recent studies of cryptophycean systematics have applied organellar genomes (complete plastid and mitochondrial DNAs). However, no comparative analysis of gene characteristics for molecular marker selection has been done because only a few taxa are available. In this study, we tested nine plastid genes (atpA, atpB, chlI, clpC, dnaK, rpoC1, secA, psaA, and tufA) with conventional genes (nuclear 18S rRNA, and plastid 16S and 23S rRNAs, rbcL, and psbA) from 30 selected taxa (12 lineages) in order to develop new markers for cryptophycean diversity. We described sequence statistics such as proportions of conserved, variable, and parsimony informative sites of each gene. We also compared and discussed the distribution of p-distance and saturation test results from the inter- and intra-cryptophycean lineages.ges contribute to significant algal blooms from winter to spring at the southwestern region of the South Sea and near Jejudo. Recent studies of cryptophycean systematics have applied organellar genomes (complete plastid and mitochondrial DNAs). However, no comparative analysis of gene characteristics for molecular marker selection has been done because only a few taxa are available. In this study, we tested nine plastid genes (atpA, atpB, chlI, clpC, dnaK, rpoC1, secA, psaA, and tufA) with conventional genes (nuclear 18S rRNA, and plastid 16S and 23S rRNAs, rbcL, and psbA) from 30 selected taxa (12 lineages) in order to develop new markers for cryptophycean diversity. We described sequence statistics such as proportions of conserved, variable, and parsimony informative sites of each gene. We also compared and discussed the distribution of p-distance and saturation test results from the inter- and intra-cryptophycean lineages.